This disclosure relates to generally to bulk storage containers, such as grain bins and grain hoppers, which hold flowable material (such as grain or the like), and, in particular, to an external device for reducing the occurrence of bridging of material at the outlet of the bulk storage container.
Bulk storage containers typically have a lower outlet through which the grain (or other flowable material) contained in the bin/hopper exits the storage container. As is known, the material within the storage device can “bridge” (e.g., form a void in the material) at exit of the storage device. This bridging can interfere with the flow of material from the bulk storage container. Various devices have been employed to break up or prevent the formation of such bridges. Some devices reside within and are supported by the container itself. Other devices are predominantly external but require some amount of modification and internal access/disturbance in order to mount. Because such devices have internal components they cannot easily be incorporated in or added to the bulk storage container at a later date. Further, because the device is at least partially internal, repair or replacement of the device can be difficult, and, at a minimum, would require emptying of the bulk storage container of its contents and decommissioning the bulk storage container during the repair. Typical devices include, for example, pneumatic pistons, non-powered and powered internal agitators, and eccentric rotary vibrators. Such devices have additional disadvantages. Pneumatic pistons require a compressed air source and pneumatic control system which may not be readily available and which require additional maintenance. Non-powered agitators do not react to bridging. Through their limited motion, they hope to prevent bridging from occurring. Powered internal agitators attempt to impart additional energy to prevent bridging, but place the source of agitation in a compromising position. Rotary vibrators typically operate at a high frequency and/or load in order to generate sufficient energy to affect the bridging. Unfortunately, due to resonance the very frequency and energy transferred to break up bridges may be detrimental and even destructive to the container itself.
It is further necessary that for whatever device is employed to eliminate such bridging that it not physically damage the bin or the discharge structure attached to the container.